This invention relates to railway couplers, and more particularly, to an improved type "E" coupler, with a top and bottom shelf.
In the past, there have been several serious wrecks on railroads involving tank cars with standard American Association of Railroads (AAR) type "E" couplers. In some cases the tank cars have carried hazardous materials which have exploded during the wreck causing loss of property and lives. During normal movement of railroad cars, the standard type "E" coupler will ride up and down on a mating coupler. The United States Department of Transportation, however, has claimed that during derailment the standard type "E" coupler will ride up and over the mating coupler and puncture the tank car.
Because the standard type "E" coupler has provided many decades of useful service for American railroads, attempts have been made to modify the "E" coupler to prevent the coupler from riding up and over its mating coupler during movement of the cars. The standard "E" coupler has been modified to include an integral top shelf and/or bottom shelf. The shelves limit the vertical movement of the mating coupler. Unfortunately, a standard "E" coupler with integral top and bottom shelves is not universally adaptable when top and bottom shelves are not wanted or considered necessary for other types of railway usage not involving tank cars carrying hazardous material.
Separable top and bottom shelves have been manufactured and selectively welded to the standard "E" coupler for use with tank cars carrying hazardous materials. Such separable shelves permit use of the standard "E" coupler without the shelves for railway usage not involving tank cars carrying hazardous materials. The separable cast top and bottom shelves are contoured to fit the existing standard "E" coupler. Unfortunately, however, it is very difficult and expensive to hold the dimensional tolerances required for such a contoured casting.